As mentioned earlier, most degradation products tend to be polymeric species containing one or several carboxylic acid groups. These colors are inclined to be large organic molecules that have a weakly negative charge. The types of resins that are typically used in these cases are ion-exchange resins that have a defined pore structure (macroreticular) or gel matrix and a positive charge derived from either a quaternary amine or tertiary amine function.
includes a list of ion exchange resins that are widely used for decolorization, but other similar products are available.
A filtered, crude vancomycin broth was adjusted to pH 8, and the broth was then pumped over a column of Amberlite FPA40 Cl using a Rainin Rabbit Pump. The column effluent was monitored with a Linear Model 200 detector (Grace Davison Discovery Science) and fractions were collected in one tube every five minutes using a Gilson 201 Fraction Collector. The experiment involved a column of 2.0 cm ID x 30 cm L and a flow rate of 1.63 mL/minute (1 CV/Hr). Detection was performed with a Thermo Fisher Scientific Biomate 3 Spectrophotometer at 400 nm.
The broth was pumped over the column for a total of five column volumes (470 mL) before the experiment was terminated and then reactions of the effluent were analyzed.
The average color removal was 50% (Figure 1) after the first column volume had passed through the column. Figure 2 shows a close-up of Rohm & Haas’ Amberlite™ FPA40 Cl column with the color adsorbed on the top of the column.
Jon Fisher is technical service manager, Americas, Amie Gehris is technical service scientist healthcare, process chemicals and biocides, and John Maikner is senior scientist healthcare, process chemicals and biocides, at Advanced Biosciences, a unit of Rohm & Haas. E-mail: firstname.lastname@example.org. Web: www.advancedbiosciences.com.